Clinicopathological characteristic of ciliated muconodular papillary tumour of the lung

Ciliated muconodular papillary tumour (CMPT) is a rare tumour characterised by tripartite cellular components of mucinous cells, ciliated columnar cells and basal cells with a predominantly papillary architecture. Its clinicopathological characteristics and treatment methods have not been fully elucidated.Twenty-six patients with CMPT diagnosed and treated in our hospital were retrospectively analysed.The cohort was composed of 13 males and 13 females, with a mean age of 64.4±5.93 years. The diameter of the primary tumour ranged from 0.3 to 1.4 cm. The lesions appeared as subsolid nodules, ground-glass nodules and cavitary nodules under the CT scan. All the patients underwent surgical treatment and did not receive postoperative adjuvant therapy. All the CMPTs were diagnosed by immunohistochemistry and not by intraoperative frozen sections. Next-generation sequencing detection demonstrated EGFR, KRAS and BRAF mutations and ALK rearrangements in CMPTs. The follow-up duration ranged from 5 to 65 months, and no case of tumour recurrence was observed until the final follow-up.The incidence of CMPT is low, and the prognosis is good. Immunohistochemistry is helpful for an accurate diagnosis of CMPT, while intraoperative frozen sections cannot fully guide the surgical method. Sublobectomy may be enough without adjuvant treatment. CMPTs exhibited a relatively high rate of driver gene mutations, while the mutation sites were not consistent with those in lung adenocarcinoma.